It’s been a month since the White House gave the official 90-day warning to Canada and Mexico that it plans to renegotiate NAFTA, a trade deal that U.S. President Donald Trump has vowed to rewrite or scrap altogether.

But David Frum, senior editor of The Atlantic, has doubts that the Trump administration will be able to close the deal.

“The Trump administration has no capacity to get things like that done. As you’ve seen, they’ve been unable to pass major legislation. Writing a treaty like this involving three countries is a major undertaking,” he told CTV’s Power Play on Thursday.

Frum pointed out that several key positions necessary to get the ball rolling have yet to be filled, including an intellectual property negotiator and several senior trade roles.

“So how do they even begin this process? And if the president were to cancel NAFTA without something in its place, that would fall heavily on a lot of pro-Trump states -- Iowa and Arkansas -- and other major agricultural exporters,” Frum said.

“I find it hard to imagine that this talk is going to turn into anything more than talk.”

Frum, a conservative political commentator and former speechwriter for George W. Bush, has been an ardent critic of Trump. Speaking to CTV’s Power Play, Frum responded to Trump’s latest Twitter outburst. On Thursday, Trump tweeted that is unfolding amid reports that he is being investigated by special counsel Robert Mueller for potentially obstructing justice.

The Washington Post has reported that the widening scope of the investigation was prompted by the firing of former FBI director James Comey, who has testified under oath that Trump demanded a vow of loyalty from him.

But there’s a basic fault in Trump’s “witch hunt” accusation, Frum said.

“The point of witch hunts is we’re supposed to believe there are no witches,” Frum told CTV’s Power Play on Thursday. “But that Russia attacked the American democratic process -- that’s just a fact. And that Donald Trump accepted that help and benefited from it and publically welcomed it, that’s also a fact.”

What is uncertain is whether Trump in any way co-ordinated with this effort. And that is a question that we’ll get to the bottom of.”

Frum suggested that Trump will face even more questions if -- as some reports have suggested -- he chooses to fire Mueller.

“If the president first fires the director of the FBI and then the special counsel, people begin to think: ‘He looks really guilty, doesn’t he?’”

Trump has nominated Kelly Knight Craft, a top Republican donor, as U.S. ambassador to Canada. Frum called Knight Craft a standard-issue Republican who is “not a friend of Trump” and suggested her appointment could be mired by delays.

“Trump has a habit, and he did this for example with the ambassador of the U.K., of announcing the nomination and then never getting it together even to submit the paperwork to the Senate, much less for the nomination to be acted upon within the Senate,” he said.

Even so, Knight Craft’s appointment isn’t expected to cause a major stir, Frum said.

“Basically it’s a pretty hard job to mess up, ambassador to Canada, it’s a very strong relationship and very little of it goes through the ambassador’s hands.”